In dynamic network because of the increasing demand for
In the last years, the electric power industry is evolving at a fast pace where new challenges
are faced. The grid needs to be adapted in order to be a more stable and dynamic network
because of the increasing demand for energy, the altering peak hours and the volatile changes.
Many of these challenges not only influence the structure of the grid by adding new types of
components, e.g. renewable energies, but also shift the entire way, how electricity is consumed.
As S. Blumsack 4 explains in his work, this shift cuts across many core aspects of the electricity
consumption such as its generation, distribution and utilization. The generation of electricity is
no longer made exclusively by fossil fuels, new sources are introduced such as the renewable
energies. The distribution is no longer solely centralized but is changing to a more decentral-
ized way of energy distribution. Decentralized energy, as the name suggests, is produced close
to where it will be used, rather than at a large plant elsewhere and sent through the local or
nearby grid. Finally, the utilization of the energy behaves more dynamically and volatile than
In the year 2007, the concept of Smart Grid (SG) was officially introduced by the Energy In-
dependence and Security Art (EISA) 15 and approved by the US Congress in the same year.
In spite of notion already applied since the 1980’s by developed countries like the US with the
introduction of the automatic meter reading 5. The concept of SG was introduced as a re-
sponse to the problems and challenges of the recent development of the grid. In addition to the
challenges mentioned above, the high level of energy demand at different hours was and it still
being a common issue. As the survey 6 shows, the consumption of energy is increasing every
year thanks to the more energy-requesting equipments and electronic appliances. This growth
of energy demand brings further issues, such as the need of a secure and reliable network. This
means that the network will ensure more reliable supply of electricity as well as its distribution,
and reduced vulnerability to energy cuts of different forms, e.g. natural disasters and attacks.
Furthermore, the urgency of a structured network is visible. The new topology of the grid should
be able to deal with large number of smaller subnetworks without being a centralized grid and
a bidirectional energy flows.
Although, SG is a term that does not have a unique definition, the description presented by the
IEEE 23 is very interesting. They described the SG as “the integration of power sources, com-
munications, and information technologies”. One of the core ideas of the SG is the distributed
sources of energy. This idea addresses one central issue presented before, the decentralized
energy. With the introduction of renewable energy sources (solar, wind, geothermal, etc.), this
issue has been sharpened. Nowadays, the energy production takes place in numerous locations
and in diverse scale, from the private user to industrial installations. SG tries to solve this issue
through new concepts and technologies such as the Distributed Energy Resources (DER) 3
As mentioned in 19, a SG is capable of communicating and processing the information in a
proactive manner, namely the grid is able to identify possible problems and take preemptory
action against them instead of reacting only when the problem already exists. The introduction
of smart objects tries to solve this issue. Smart objects are active, digital, networked objects
that can operate to some extent autonomously and are reconfigurable. They also have local
control of the resources such as energy, data storage, etc.26. Some interesting examples are bidirectional smart meters and smart gadgets such as smart light bulbs or smart power sockets.
Bidirectional smart meters allow the user to control and monitor the flow of energy in both
directions. Smart gadgets are physical objects that can be programmed to turn on or off au-
tonomously in certain circumstances.
Despite the concept of SG is a very promising approach, it also introduces some challenges and
difficulties. One of the most considerable problems remained the integration of the renewable
energies. These sources of energy represent a big challenge for the SG because of the fluctuating
and unpredictable nature like solar photovoltaic and wind mill. Their volatile nature changes
within minutes influencing the amount of energy that they produce, hence the price varies as
well. As mentioned in the annual report from the REN21 27, the renewable sources represent
almost 20% of the worldwide total production of electricity. As it is shown in Fig. 1.1 and Fig.
1.2, the growth of this kind of sources is increasing exponentially. The major challenge with
this types of energy sources is the volatile and constant change that depends merely on climate
factors. For instance, a solar park produces energy during the day and, at night its production
is almost null. In between, the amount of energy produced oscillate. Hence, this kind of incon-
stant states implies a certain capacity of the flexibility of the grid inasmuch as the renewable
sources have different types of behavior and requirements of operation. The SG has to be capa-
ble to change dynamically its state and flow of energy depending on the amount of energy that
the renewable sources produce.
As mentioned above, renewable energies involve further complications regarding the distribu-
tion of the production sources. Users from the private sector have also the possibility to utilize
this types of technologies in a small scale. For example, a household can install a set of solar
modules in its roof. Thus, it produce its own energy. This new type of object which produce
and consume energy at the same time is called prosumer 28. Despite the small quantities of
energy that these prosumers generate, these add to a significant amount of energy that, in the
end, destabilize the network. This destabilization is susceptible to happen because of the low
consumer support. As C. Vineetha 33 explains in his work, the lack of consumer support is a
factor that SG technologies have to consider. For instance, an user from the private sector that
uses renewable sources and some sort of energy storage like batteries, can be transformed into a pure energy producer at a certain point in time. Therefore, the grid not only has to be capable
of solving this problem physically but also immaterially meaning being able to process the data
and change its structure and the flow of energy.
Many studies have been made in this field developing interesting concepts and propositions.
Some examples are the above mentioned Distributed Energy Resources (DER) 9, Wireless
Power Transfer (WPT) 21, Electrical Energy Storage (EES) 8, etc. WPT addresses the issue
of transmission of large power levels over moderate distances by using the wireless technology.
In the article of Miller et al. 21, this problem is focused in the charge of electrical vehicles.
Apart from that, Dunn et al. reviews some of the new state-of-art storage systems like the redox-
flow batteries and lithium-ion batteries. Notwithstanding these breakthroughs, the field of SG
needs to be complemented with more in-depth researches. It is necessary to conduct more ex-
periments in order to find better solutions to the above mentioned challenges.
In particular, we believe that some of this challenges can be be addressed successfully with the
help of Heuristic Algorithms. We propose a modified version of the so-called Particle Swarm